Fujitsu Corporation

Youichi Akasaka

Motoyoshi Sekiya

Tadashi Ikeuchi

Jeng-Yuan Yang

Inwoong Kim

Hiroki Ooi

Satoru Okano

Takuji Maeda

Takeshi Hoshida

Takao Naito

Daniel Bihon

Kentaro Nakamura

Olga I Vassilieva

Richard Colter

Satoshi Mizutani

A fixed input current is provided to a pump laser of an optical pumping block. Further, a first tuning temperature is provided to the pump laser while providing the fixed input current. The first tuning temperature is based on a target band of a pumping beam and causes the pump laser to generate a light beam having a first frequency band that is dictated by the first tuning temperature and the fixed input current. Further, a second tuning temperature is provided to a temperature dependent optical reflector configured to receive the light beam. The second tuning temperature is based on the target band of the pumping beam and causes the optical reflector to reflect light of the light beam that is within a second frequency band that corresponds to the target frequency band. The reflected light beam is emitted into a transmission optical medium configured to carry an optical signal.

Raman optical amplifier with fabry-perot pump laser

According to an aspect of an embodiment, operations may include obtaining a respective target temperature for each respective segment of multiple segments of a Highly Non-Linear optical Fiber (HNLF). Each respective target temperature may be based on a respective Zero-Dispersion Wavelength (ZDW) distribution of its corresponding segment and may be based on a target ZDW of the HNLF. The operations may also include adjusting a respective temperature of each respective segment that may be based on the respective target temperature of each respective segment such that each respective segment has a respective ZDW that is within a threshold of the target ZDW.

Stimulated Brillouin scattering suppressed highly non-linear optical fiber

An optical device may include a non-linear optical medium and an optical coupler coupled to the optical medium. The optical coupler may be configured to multiplex an optical data signal and an optical pump signal onto the optical medium such that an optical idler signal is generated. The power of the optical pump signal may be below a level that results in optical parametric amplification of the optical idler signal. The optical device may further include an amplifier coupled to the optical medium and configured to amplify the optical data signal.

Optical signal power gain

An optical system for suppressing signal noise on an optical fiber, including an input power signal; a pump laser configured to receive the input power signal; a phase modulator coupled to the pump laser configured to modulate, in response to the input power signal, a phase of the pump laser to increase a stimulated Brillouin scattering (SBS) threshold of the pump laser, wherein the pump laser is further configured to: increase a power at the pump laser to be greater than the SBS threshold; generate a back scattering power based on the power of the pump laser being greater than the increased SBS threshold; and limit an output power signal of the pump laser based on the generated back scattering power.

Suppressing signal noise on an optical fiber

According to an aspect of an embodiment, operations may include receiving a light wave and generating a pumping wave by performing polarization modulation on the light wave based on a bit stream. The pumping wave may include a first polarization component having a first polarization and a second polarization component having a second polarization and having a same wavelength as the first polarization component. The operations may also include emitting the pumping wave in an optical medium such that the pumping wave amplifies an optical signal propagating within the optical medium.

Dual polarization optical pumping

An optical system, comprising a first wavelength conversion module to: adjust a power of a first pump wavelength; couple an input signal with the first pump wavelength to generate a first coupled signal; perform a first wavelength conversion of the first coupled signal to generate a first wavelength converted signal, the power of the first pump wavelength is adjusted such that the first wavelength conversion is performed with 0 dB conversion efficiency; the optical amplifier to amplify the first wavelength converted signal; a second wavelength conversion module to: adjust a power of a second pump wavelength; couple the amplified first wavelength converted signal with the second pump wavelength to generate a second coupled signal; perform a second wavelength conversion of the second coupled signal to generate a second wavelength converted signal with 0 dB conversion efficiency.

Optical amplification in an optical network

A low-noise amplifier includes a gain medium and two or more amplifier stages. Each amplifier stage includes an optical filter to pass all wavelengths of a respective input optical signal in a given propagation direction over the gain medium and reflect wavelengths above a respective threshold wavelength received in the opposite direction, and a respective Raman pump to inject a pump light centered at a wavelength lower than the threshold wavelength onto the gain medium for transmission in the given direction. A first amplifier stage outputs a first combined optical signal including all wavelengths of the respective input optical signal and a pump light injected by the respective Raman pump. The second amplifier stage receives the first combined optical signal as its input and outputs a second combined optical signal including all wavelengths of the first combined optical signal and a pump light injected by the respective Raman pump.

Low-noise Raman amplifier

An optical system including a transmission fiber to transmit a WDM input optical signal between first and second points; a second order forward Raman pump module positioned along a first region of the transmission fiber proximate to the first point; a first order backward Raman pump module positioned along a second region of the transmission fiber proximate to the second point, the first order backward Raman pump module is configured to generate a first pumping light along the transmission fiber to amplify the WDM input optical signal at the second region of the transmission fiber, wherein the second order forward Raman pump module is configured to generate a second pumping light along the transmission fiber to amplify the first pumping light generated by the first order backward Raman pump module, wherein the amplified first pumping light amplifies the WDM input optical signal at the first region of the transmission fiber.

Optical system for compensating for signal loss

An optical system including a forward and a backward Raman pump module positioned along a transmission fiber; a noise matrix computing module configured to: determine, for first gains of the optical signal, a first noise associated with the first gain of the forward Raman pump; determine, for second gains of the optical signal, a second noise associated with the second gain of the backward Raman pump module; generate a noise matrix based on i) the first noise for each first gain of the forward Raman pump module and ii) the second noise for each second gain of the backward Raman pump module; identify a span loss of the optical signal as the optical signal is transmitted along the transmission fiber; identify a combination of a particular first gain of the forward Raman pump module and a particular second gain of the backward Raman pump module.

An FBG element is configured to apply a phase shift to at least one of an input optical signal, a first pump light, and an idler signal between stages of a phase sensitive amplifier. The FBG element is apodized using a trapezoidal apodization function over the length of the first FBG element to enable tuning of the phase shift over a range of 2&#x3c0; radians.

Phase shifter for an optical phase-sensitive amplifier

An optical system for controlling gain modification, including a first non-linear optical element (NLE) through which an input optical signal and a first pump wavelength are transmitted to generate a first optical signal; a second NLE through which the first optical signal is amplified to generate a second optical signal; a third NLE through which the second optical signal is amplified to generate a third optical signal; a first heating element coupled to the second NLE to adjust a temperature of the second NLE to control a first gain profile of the second optical signal; a second heating element coupled to the third NLE to adjust a temperature of the third NLE to control a second gain profile of the third optical signal, wherein the temperatures of the second and the third NLE minimize a gain modulation of the optical system based on the first and the second gain profiles.

Controlling gain modulation in optical communication networks

Phase modulation of an output optical signal from a phase-sensitive amplifier may be used to perform phase adjustment for optimal phase-sensitive amplification. Specifically, when the optical pump is phase modulated to suppress SBS, a second phase modulator may be used to counter dither the first phase modulator. Both phase modulators may be controlled by a phase shifter. Intensity modulation of the output optical signal may also be performed to reduce noise. In this manner, the OSNR of the output optical signal may be increased.

Optical phase-sensitive amplifier with signal noise removal

Methods and systems for intra data center optical switching of optical signals use an intra data center optical switch to optically transmit N optical wavelengths as an optical signal transmitting a data stream generated by a data center system included within N data center systems. The data center system may selectively receive one of N&#x2212;1 optical wavelengths as another optical signal corresponding to one of N&#x2212;1 other data center systems excluding the data center system from the intra data center optical switch. In this manner, intra data center optical switching may be performed without utilizing Ethernet and optical switches, which may result in reduced power consumption for data center communication.

Intra data center optical switching

Methods and systems enable amplifying optical signals using a Bragg reflection waveguide (BRW) having second order optical nonlinearity to generate an optical pump by injection locking. The BRW may also be used for parametric amplification of optical signals using the optical pump. Feedback phase-power control may be performed to maximize output power.

Harmonic generation and phase sensitive amplification using a bragg reflection waveguide

Methods and systems for implementing a low noise CDC ROADM include incorporating individual stages of an optical PSA before and after WSSs included in the CDC ROADM. The WSSs may be used to route the pump and idler signals, as well as to perform phase tuning for optimal phase-sensitive amplification.

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Allen, TX, United States of America

Youichi Akasaka